Raking apparatus

ABSTRACT

The present invention provides a cylindrical rake for use in a raking apparatus wherein the cylindrical rake comprises first and second end members spaced apart from one another along the axis of the cylindrical rake, a plurality of circumferentially spaced elongated tine carrying members which extend between and are carried by first and second end members mounting devices for mounting the rake on a suitable carriage thereof, and a driven device adapted to be driven for rotating the rake about its axis in use. The tine carrying members carry a plurality of tine elements thereon; characterized in that each tine element is constituted by a length of wire which is formed into two axially spaced coils, a respective neighboring two of the tine carrying members being inserted one each through the two coils for carrying the tine element on the two respective tine carrying members, and each tine element has at least one free end of the wire which extends outwardly of the cylindrical rake for engaging the ground in service. The invention also provides a raking apparatus comprising such a cylindrical rake, a carriage device adapted for translational movement over the ground and a rotating device for rotating the cylindrical rake.

The present invention relates to a raking apparatus for raking orscarifying lawns and other fine turf areas such, for example, as golfcourse greens, tennis courts, bowling greens and cricket creases. Theraking apparatus of the present invention can also be used on areas ofartificial grass such as that which is available commercially under thetrade name ASTROTURF.

In order to maintain a grass lawn or other turfed area in good conditionit is necessary regularly to remove from the grass nap any materialswhich obstruct the flow of air between the individual blades of grassand the underlying soil; the nap must be allowed to "breathe" in orderto permit proper drying. Such obstructing materials include patches ofmoss, debris such as fallen leaves and also blades of grass which growgenerally horizontally in the nap. A typical grass lawn may comprise asubstantial proportion of grass which grows otherwise than vertically,and such grass can have an injurious effect on the condition of the lawnoverall. It is of course also necessary to remove any rotting matter.

These lawn treatments have been traditionally carried out manually usinga hand-operated lawn rake of the kind well known in the art comprising ahand-held elongate shaft which carries a rake-head at one end. The headcomprises a plurality of elongate tines which are typically disposed ina common plane and splayed outwardly with respect to one another fromthe end of the shaft. One or more cross-pieces are usually provided toreinforce the tines, and the tines themselves are typically cranked attheir extremities for engaging the ground. Traditional hand rakes ofthis kind are widely used in commercial and domestic gardening, and aregenerally satisfactory for de-thatching lawns and other grassed areas ofmoss deposits, and for lifting horizontally growing blades of grass. Theuse of a traditional hand rake is however very time-consuming, and istherefore not practical for use on very large areas of grass such, forexample, as tennis courts and particularly golf courses.

Many tennis courts are now being constructed using artificial grass(e.g. that which is commercially available under the trade markASTROTURF) which has a carpet-like construction comprising a flexiblebacking sheet in which are anchored a plurality of synthetic piles whichform a nap. As will be well known to a person skilled in the art, sandis brushed into the nap of artificial grass prior to use. Theinterstitial spaces between the piles of the grass are filled with thesand to a predetermined depth, such that only the extremities of thepiles, remote from the backing layer, project above the layer of sand.In a typical artificial grass assembly, the pile has a length of about18 mm, and the sand is filled to a depth of about 12 mm, such that about6 mm of the pile projects above the sand. Of course, the depth of thesand used will vary according to the application for which theartificial grass is required.

A problem associated with the use of artificial grass of the kinddescribed above, is that from time to time the sand in the nap must bereplaced. This entails removing the existing sand, and then replenishingthe artificial grass with fresh sand. Traditional hand rakes of the kinddescribed above are wholly unsuitable for removing the sand from an areaof artificial grass.

U.S. Pat. No. 4,344,273 discloses an automated lawn scarifier whichcomprises carriage means adapted for translational movement over theground, particularly natural or synthetic grass, a cylindrical rakemounted on the carriage means for rotation about its axis injuxtaposition with the ground, and rotating means for rotating thecylindrical rake; which cylindrical rake comprises a plurality ofelongate tine-carrying members spaced around the circumference of therake, which tine carrying members carry a plurality of tine elementsthereon. Each tine element of the U.S. Pat. No. 4,344,273 scarifier isconstituted by a torsion coil spring comprising a single coil and twoprotruding free ends. A respective one of the tine-carrying members isinserted through the coil of each spring for carrying the tine elementon the respective rod. One of the free ends of each tine element extendsoutwardly of the rake for engaging the ground in service; the other freeend is located between another neighbouring tine-carrying member and anaxle which extends between the first and second end members on the axisof the rake.

The use of the axle for anchoring the other free end of each tineelement against the said other neighbouring tine-carrying member,however, effectively limits the maximum diameter of the cylindricalrake, the number and spacing of tine carrying members, and hence theoverall number and density of tines on the cylindrical rake. Further therestriction on the maximum diameter of the cylindrical rake imposes anupper limit on the tine velocity which can be achieved for a givenoutput speed of the rotating means. Not only does this limit theoperating efficiency of the scarifier, in terms of the power developedby rotation of the cylindrical rake, but also limits the flux of airthrough the cylindrical rake which is generated by rotation of the rake;this in turn limits the maximum "throw-speed" of the scarifier. The neteffect is that whilst the U.S. Pat. No. 4,344,273 scarifier operatesgenerally satisfactorily for scarifying domestic lawns, it is notsuitable for use on a large commercial scale for raking golf greens orthe like. Nor is it suitable for removing sand from the nap ofartificial grass.

It is an object of at least the preferred embodiments of the presentinvention therefore to provide an improved raking apparatus which can beused inter alia, for removing stolens, moss and other detritus fromgrass. In particular it is an object of those embodiments to provide araking apparatus which can be used for treating large areas of grasssuch, for example, as golf courses and tennis courts.

It is yet another object of the preferred embodiments to provide araking apparatus which is sufficiently robust that it is suitable forheavy use, and which can preferably be easily disassembled for repairwhen necessary.

It is yet another object of the preferred embodiments to provide araking apparatus which has a sufficient "throw-speed" to make the rakesuitable for removing efficiently sand from the nap of an artificialgrass.

Accordingly, in one aspect of the present invention there is provided araking apparatus which is characterised in that each tine element isconstituted by a length of wire which is formed into two spaced coils,two respective (preferably neighbouring) tine-carrying members beinginserted one each through the two coils for carrying the tine element onthe two respective tine-carrying members, and has at least one free endof the wire which extends outwardly of the cylindrical rake for engagingthe ground in service.

In another aspect, the raking apparatus is characterised in thatrespective pairs of tine elements are constituted by opposite ends of acontinuous length of wire supported and located by two of thetine-carrying members.

The tine carrying members may be supported by two or more spaced supportmembers positioned for example at the ends of the cylinder and ifnecessary also intermediately between the ends.

In a different aspect the invention includes a method of raking an areaof natural or synthetic grass using a raking apparatus of the presentinvention.

In some embodiments, a receptacle may further be provided for receivingmaterial raked up by the raking apparatus in service. Said receptaclemeans may comprise a bin of the kind which is well known in the lawnmower art, which bin is detachably mountable on the front of thecarriage in juxtaposition with the cylindrical rake. A throwplate may beprovided for deflecting material raked up by the cylindrical rake inservice into the bin.

Typically the raking apparatus of the present invention, apart from thecylindrical rake component, may be of similar construction to aconventional lawn mower. The carriage may include one or more wheels orrollers to allow movement of the apparatus over the ground. The carriagemay be powered or, in the alternative, may be adapted to be pushed overthe ground by an operator. As with conventional lawn mower technology, apowered raking apparatus in accordance with the invention may beelectrically powered or may include a motor which is driven by thecombustion of a combustible fuel such, for example as a single-strokepetrol engine.

In the case of a non-powered raking apparatus, the rotating means mayinclude a step-up gear mechanism between the wheel(s) or roller(s) ofthe carriage and the cylindrical rake. Alternatively in the case of apowered raking apparatus, the cylindrical rake may be driven directly bythe motor.

The cylindrical rake may be disposed ahead of the carriage wheel(s) orroller(s) in the forward direction of movement of the apparatus, and aheight-adjustable roller or wheels may be provided, usually forwardly ofthe cylindrical rake, to support the cylindrical rake at an adjustableheight above the ground.

In another aspect of the present invention, it is envisaged that thecylindrical rake may be adapted for use in an existing lawn mower, insubstitution for the cylindrical blade unit. To this end, the presentinvention specifically includes the cylindrical rake on its own, as wellas in combination with the carriage and rotating means, said cylindricalrake further comprising mounting means for mounting the cylindrical rakeon the carriage means, and means for drivingly rotating the cylindricalrake in use.

Said support members may each comprise a flat disk which supports thetine-carrying members juxtaposed its periphery. Each tine-carryingmember may consist of a rod which is provided at least one end with areleasable fastening means for the supporting end member. The other endof each rod may be welded or otherwise fixedly secured to the other enddisk. Alternatively, both ends of the rod may be releasably secured tothe end disks. The cylindrical rake may therefore comprise a hollowcylinder defined by the end disks and circumferentially disposed rods;the central shaft may be omitted between the end discs if the structureis made rigid enough. In use, a flow of air is generated between therods and through the interior of the rake. This flow of air assists inthrowing material raked-up by the rake clear of the rake and into thereceptacle means if fitted.

In some embodiments the tine carrying members may be skewed with respectto the axis of the cylindrical rake, such that the tines are disposed ona plurality of helical paths around the cylinder.

In yet another aspect of the present invention, a sufficient number oftine elements may be carried on each tine carrying member such that eachtine element butts against and is prevented from axial movement withrespect to the cylinder by its two neighbouring tine elements. Theend-most tine elements may butt against and be held in place by thefirst and second end members. In this way the cylindrical rake may havea high density of tines, thereby facilitating efficient raking ofnatural or synthetic grass.

In yet another aspect of the present invention, both free ends of eachtine element may extend tangentially to their juxtaposed coil to providea tine. As each tine element is carried on two spaced tine carryingrods, each tine element is held in place with respect to rotation aboutthe axes of its two respective tine carrying members, and each of thetwo tines defined by the wire is disposed juxtaposed a respective one ofthe two neighbouring tine-carrying members.

The two free ends of the wire will usually both subtend an angle withthe line between the centres of the two coils. These angles may be thesame or different. Preferably each free end will be disposed so as todefine an angle between 20-60°, typically about 45°, to the horizontalwhen its respective tine-carrying member reaches the lowest part of itslocus in use.

In another aspect of the present invention there is provided a tineelement for a raking apparatus in accordance with the present invention,which tine element comprises a length of wire which is formed into twospaced coils and has at least one free end of the wire which extendstangentially to the juxtaposed coil to provide a tine for raking, whichcoils are arranged such that their respective axes are disposedsubstantially parallel to one another and such that these axes arespaced from one another, in a direction orthogonal to the axes, by adistance which is at least equal to the average diameter of the twocoils.

Another aspect of the invention provides a tine element for acylindrical rake, which tine element comprises a length of wire which isformed into two coils spaced laterally of each other, the free ends ofthe wire each extending from its juxtaposed coil to provide a tine forraking, which coils are arranged such that their respective axes aredisposed substantially parallel to one another.

Preferably, when the angle between the tines is θ degrees, the anglebetween one tine and a line joining the axes of the coils is φ+θ/₂degrees, the angle between the other tine and the line being φ-θ/₂degrees, where φ is the angle made by the tines to the horizontal whenin their lowest position after fitting to a rotor as set forth above.

A further aspect of the invention provides a tine-element for acylindrical rake, which tine element comprises a length of wire which isformed into two coils spaced laterally of each other and has at leastone free end of the wire which extends tangentially to the juxtaposedcoil to provide a tine for raking, which coils are of substantiallyequal diameter and are arranged such that their respective axes aredisposed substantially parallel to one another.

The two coils of the tine element of the present invention can thusreceive two respective tine-carrying members for carrying the element onthe cylindrical rake according to the invention, and thereby to preventrotation of the tine element with respect to said tine carrying members.

The use of spaced end members, tine-carrying embers extending betweenand carried by the end members, and tine elements which can be threadedonto the tine-carrying members enables a cylindrical rake to be providedwhich, in accordance with a particular aspect of the invention, may havereleasable fastenings between the tine-carrying members and the endmembers, thereby facilitating ready disassembly and reassembly of therake as and when required, e.g. in the event of a tine element breaking.

Furthermore, the use of tine elements in accordance with the presentinvention which have at least two coils for carrying the tine element ontwo respective tine carrying members means that the cylindrical rake canbe made to any practical diameter, and with any suitable number of tinecarrying members. This enables the cylindrical rake according to theinvention to be constructed with a total number and density of tines,and with a sufficient throw-speed and tine velocity in service, whichrenders the rake suitable for use on a commercial scale.

Following is a description by way of example only and with reference tothe accompanying drawings of methods of carrying the present inventioninto effect.

In the drawings:

FIG. 1 is a perspective view of a raking apparatus in accordance withthe present invention.

FIG. 2 is a perspective view, partly cut-away, of a cylindrical rakeincluded in the raking apparatus of FIG. 1, with tine elements and threetine-carrying members removed for clarity.

FIG. 3 is side view of a part of the drum rake of FIG. 2, showing an endplate and a plurality of tine-supporting rods.

FIG. 4 is an end view of a tine unit in accordance with the presentinvention.

FIG. 5 is a side view of the tine unit of FIG. 4.

FIG. 6 is a cross-sectional view of the line III--III in FIG. 2, with anumber of tine elements shown in the fitted position.

A raking apparatus (10) in accordance with the present inventioncomprises a carriage (20) which is adapted for translational movementover the ground, particularly on a natural or synthetic grass surface.The carriage (20) includes a rear roller (not shown) which supports thecarriage off the ground and an upstanding handle (22) for an operator topush the apparatus forwardly and for steering. The carriage supports asingle-cylinder petrol engine (24) and a fuel tank (26). Alternatively,an electric motor may be employed, and a flexible cable provided forconnecting the electric motor to a suitable supply.

The engine (24) is arranged to drive the roller through a step-down gearmechanism or belt drive (not shown).

Forwardly of the roller, the carriage (20) includes two forwardlyextending arms (30, 32) which carry between them a cylindrical rake (50)(shown schematically in FIG. 1).

The cylindrical rake (50) is arranged to be driven by the motor (24)through a step-up gear mechanism or belt drive (not shown) in the samedirection of rotation as the rear roller, as the raking apparatus ismoved forwardly over the ground.

Forwardly of the cylindrical rake (50), the arms (30, 32) carry betweenthem a height-adjustable forward roller (34) which can be adjusted tospace the cylindrical rake (50) at a pre-determined height above theground. The arms (30, 32) are also adapted to carry a collection bin(not shown) of the kind which is used in conjunction with lawn mowers.The bin includes a wide mouth which, in the fitted position, facesrearwardly in juxtaposition with the cylindrical rake. Behind thecylindrical rake (50), the carriage (20) includes a throw-plate (36)which is shaped to direct material raked up by the drum in service intothe bin. The bin is easily detachable from the carriage for emptying.Thus, except as regards the cylindrical rake (50) (to be describedhereafter) the apparatus is similar to a conventional motorised cylinderlawn mower.

Said cylindrical rake (50) includes an axle (52) (see FIG. 2) whichextends between the two arms (30,32). One end (54) of the axle issplined for engagement with the step-up gear mechanism. The said one end(54) is also formed in an external thread (56) for engagement with aclutch mechanism (not shown).

The axle (52) carries two circular end plates (60, 62) at opposite endsof the axle (52) (as shown in FIG. 2) and an intermediate plate (64). Ofcourse, in some embodiments, more than one intermediate plate may beemployed. Each of the end and intermediates plates (60, 62, 64) isdrilled centrally at (66) to form a square aperture which accommodatesthe axle (52). The axle (52) is of square cross-section such that itkeys in the square apertures (66) of the plates (60, 62, 64). Naturally,rectilinear sections other than square may be used for the axle andcorresponding apertures (66) if desired, e.g. hexagonal.

The intermediate plate (64) is located approximately equidistant the endplates (60, 62) by two tubular sleeves (63) as shown in FIG. 2, whichtubular sleeves are fitted over the axle (52).

The plates (60, 62, 64) carry between them a plurality ofcircumferentially spaced intermediate rods (70), of equal diameter, eachrod extending between the end plates (60, 62) and passing through holesdrilled in juxtaposition with the circumference of the intermediateplate (64). In the embodiment shown in the drawings, eight intermediaterods are used, although again it will be understood that more or fewermay be used as required. Typically, the overall width of the cylindricalrake will be between 1 and 3 feet, typically about 1 1/2-2 feet from endto end. The end and intermediate plates (60, 62, 64) may each have andiameter of about 80-140 mm, typically about 110 mm.

As shown in FIG. 3, each intermediate rod (70) is threaded at each endand is secured in place by means of lock-nuts (72).

With reference to FIGS. 4 and 5 a tine unit (80) in accordance with thepresent invention is fashioned from a length of resilient wire (82).Said length of wire (82) is formed into two spaced coils (84), each coilcomprising a plurality of turns (85)--in the present example each coilincludes five turns. This defines an axial thickness of about 7 mm. Theinternal diameter of each coil (84) is the same as the external diameterof the intermediate rods (70), with a small clearance to allow anintermediate rod (52) to be threaded through the coil (84). The coilsare arranged such that their respective axes are oriented substantiallyparallel to another, and the spacing between the axes of the coils isabout equal to the spacing between two neighbouring intermediate rods(70) on the drum rake (50).

The two free ends (86) of the length of wire (82) are arranged to extendcircumferentially with respect to their juxtaposed coils (84) as shownin FIG. 4, to form tines. In this embodiment the free ends (86,87)extend such that in use each free end subtends an angle of 45° to thehorizontal when the juxtaposed intermediate rod (70) is at the lowestpoint of its locus. This is achieved by arranging the free ends suchthat one subtends an angle of 22.5° (45°-22.5°) to the line between thecentres of the coils (84), and the other subtends an angle of 67.5° (45+22.5°) thereto. This latter angle depends on the number of intermediaterods (70) used in the rake, in this case eight. In general, fordouble-ended tine members 80, the angle θ between the tine ends (86,87)is equal to 360 r/n degrees where n is the number of rods 70 and r isthe interval between the rods supporting the tine member, that is fortine members supported on neighbouring rods r=1; if supported onalternate rods r=2, etc. It is preferred, but not essential, that thetines are supported on neighbouring rods.

If the tines are to make an angle of φ to the horizontal at the lowestpoint, then they must respectively be inclined at φ+θ/2 and φ-θ/2 to theline between the centres of the coils. The angle φ is constant,typically 45°.

The length of each free-end (86,87) will depend on the particularapplication for which the apparatus is intended. However, in the exampleillustrated in FIG. 4 which is suitable for scarifying an area of fineturf, the tines may extend outwardly such that, in the true radialdirection, they project by about 23 mm. It will be understood that whenused on artificial grass, the height of the forward roller will have tobe adjusted carefully such that the tines do not impinge on the backinglayer which is, in general, easily damaged.

A plurality of tine units (80) of the kind shown in FIGS. 4 and 5 arecarried by pairs of neighbouring intermediate rods (52) as shown in FIG.6. Sufficient tine units (80) are used, such that each tine unit (80)butts against a neighbouring tine unit, and the end-most tine units (80)butt against the end and intermediate plates (60, 62, 64), such thateach tine unit is prevented from moving along the intermediate rods (52)in the axial direction of the cylindrical rake (50). In someembodiments, the tine units (80) may be carried on separate pairs of theintermediate rods (52), such that the tine units (80) carried by oneintermediate rod (52) are also carried exclusively by one otherneighbouring rod (52) as shown by the tine units (80) in full blocklines in FIG. 6. Alternatively, the tine units (80) may be distributedon the intermediate rods (52) such, for example, as by each intermediaterod (52) carrying tine units (80) with both of its neighbouring rods(52) as shown by the dashed line (80) in FIG. 6.

In each case, the tine units are carried by the intermediate rods (52),such that the free ends (86) of each unit (80) extend radially outwardlyof the cylinder and trail with respect to the rotation of the cylinder(50). It will be calculated that the cylindrical rake (50) hereinbeforedescribed will carry approximately 270 tine units (80), making a totalof about 540 tines. The tine density of the cylindrical rake (50)according to the present invention may therefore be in the range 50-150tines/m², typically about 110 tines/m².

In some embodiments, e.g. as shown in FIG. 2, the end and intermediateplates (60, 62, 64) may be arranged one with respect to the others suchthat the intermediate rods (52) are skewed with respect to the axle (52)of the drum rake (50). In this case, the tine units (80) will bedistributed on helical paths with respect to the drum (50). Of course,the present invention also includes the situation where the intermediaterods (70) are not so skewed.

The wire used to form the tine units (80) may be resilient steel wirehaving a gauge of between 0.5 and 3 mm; advantageously a gauge ofbetween 1 and 2 mm may be used, typically about 1 mm.

The present invention therefore provides a raking apparatus which can beused on natural or synthetic grass. The raking apparatus can be used fortreating fine turf areas for removing non-vertically disposed blades ofgrass, moss and other detritus, or can be used to remove the sand froman area of artificial grass for renovation of the artificial grass. Theraking apparatus includes a cylindrical rake which in service is rotatedabout its axis, and a plurality of tines are carried on a plurality ofrode which extend from one end of the cylinder to the other. The tinesare defined by tine units (80), each of which tine units (80) isfashioned from a length of wire to form two spaced torsion coils (84).The tine units (80) are carried on the tine-carrying members by means ofthe coils (84), and this has the effect of preventing rotation of thetine units (80) about their respective supporting tine-carrying members.The cylindrical rake can thus be made to any desired diameter, and withany number and density of tine-carrying member and tine units (80).Large diameter cylindrical rakes according to the invention can be madefor commercial use which may include several hundreds of tines, possiblyup to one thousand tines, and such large diameter, hollow rakes willgenerate substantial flows of therethrough in service to providesatisfactory "throw" of raked up material.

The arrangement is robust, and the combination of high tine density androbustness makes the rake of the present invention eminently suitablefor use on a commercial scale for treating, e.g golf courses, cricketpitches and the like. Moreover, it has been found that when used on fineturf areas, the raking apparatus of the invention efficiently removesnon-upright blades from the nap.

In a different trial, a motorised raking apparatus as hereinbeforedescribed was able to remove the sand from an artificial grass tenniscourt down to a depth of about 5mm in under 5 hours; this should becompared with the many days which it would take using a traditional lawnrake.

Although the described embodiment of the invention is apedestrian-controlled machine, the invention is of course equallyapplicable to other turf-care equipment conventionally provided withcylindrical grass-cutters. Thus it may be embodied in ride-on machineswhere one or more scarifying cylinders may be provided. Alternatively itmay be embodied in a trailed configuration towed behind a tractor,particularly a small low ground-pressure machine such as a garden orgreen-keeping tractor. Whilst in the described embodiment the scarifyingrotor is conventionally driven by a belt from the engine, in morecomplex embodiments, especially those with multiple rotors, it isconvenient to drive the rotors by individual hydraulic motors poweredfrom a hydraulic pump on the tractor or other ride-on machine.Alternatively in towed arrays or small pedestrian units it is possibleto drive the rotor or rotors from the ground wheels supporting thecarriage in which the rotor(s) is/are mounted, but this in general isunlikely to be the optimum solution because the increased resistance torotation of the ground wheels may cause skidding, leading to damage tothe lawn or green, and also incomplete scarification.

Each feature disclosed in this specification (which term includes theclaims) and/or shown in the drawings may be incorporated in theinvention independently of other disclosed and/or illustrated features.

I claim:
 1. A cylindrical rotary rake for use in a raking apparatus,which cylindrical rake comprises a plurality of elongate tine-carryingmembers spaced around the circumference of the rake, and mountingspermitting mounting of the rake on a suitable carriage for drivenrotation about its axis, which tine-carrying members carry a pluralityof tine units thereon; each tine unit comprising a pair of tines,wherein respective pairs of tines are constituted by opposite ends of acontinuous length of wire supported and located by two of thetine-carrying members.
 2. A raking apparatus comprising a carriageadapted for translational movement over the ground, particularly naturalor synthetic grass, a cylindrical rake as claimed in claim 1 mounted onthe carriage for rotation about its axis in juxtaposition with theground, and a drive for rotating the cylindrical rake.
 3. A rakingapparatus as claimed in claim 2, further comprising a receptacle forreceiving material raked up by the raking apparatus in service.
 4. Acylindrical rake as claimed in claim 1 wherein each tine unit is formedinto two spaced coils intermediate its ends, a respective two of thetine-carrying members being inserted one each through the two coils forcarrying the tine unit.
 5. A cylindrical rake as claimed in claim 4comprising first and second end members spaced apart from one anotheralong the axis of the cylindrical rake, and supporting the tine-carryingmembers.
 6. A cylindrical rake as claimed in claim 5 wherein said firstand second end members each comprise a flat disk which carries thetine-carrying members juxtaposed its periphery.
 7. A cylindrical rake asclaimed in claim 5 wherein each tine-carrying member consists of a rodwhich is provided at least one end with a releasable fastener forfastening to the juxtaposed end member.
 8. A cylindrical rake as claimedin claim 5, wherein each free end of the wire is arranged so as todefine an angle between 20-60°, preferably about 45°, to the horizontalwhen its respective tine-carrying member reaches the lowest part of itslocus in use.
 9. A tine unit for a cylindrical rotary rake which tineunit comprises a length of wire which is formed into two coils, eachfree end of the wire extending from its juxtaposed coil to provide atine for raking, which coils are arranged such that their respectiveaxes are disposed substantially parallel to and laterally spaced fromone another by a distance which is at least equal to the mean diameterof the two coils.
 10. A tine unit as claimed in claim 9, wherein whenthe angle between the tines is θ degrees, the angle between one tine anda line joining the axes of the coils is φ+θ/2 degrees, the angle betweenthe other tine and the line being φ-θ/2 degrees, where φ is the anglemade by the tines to the horizontal when in their lowest position afterfitting to a said rake.
 11. A tine unit as claimed in claim 9 whereinthe two coils are of substantially equal diameter.
 12. A tine unit asclaimed in claim 9 wherein each tine extends tangentially from itsjuxtaposed coil.
 13. A tine unit as claimed in claim 9 wherein each tineextends from its juxtaposed coil at an angle to a line joining the axesof the coils.
 14. A method of raking a lawn or other fine turf areausing a cylindrical rake comprising a plurality of elongatetine-carrying members spaced around the circumference of the rake, andmountings permitting mounting of the rake on a suitable carriage fordriven rotation about its axis, which tine-carrying members carry aplurality of tine units thereon; each tine unit comprising a pair oftines, wherein respective pairs of tines are constituted by oppositeends of a continuous length of wire supported and located by two of thetine-carrying members.